Reliability quantification and gait loading asymmetry assessment with wearable insoles in transfemoral amputee people at different speeds

Abstract

Introduction Amputee people have gait defaults, as for example loading asymmetry, which increase with daily living situations. Replication of realistic daily living environment in a motion analysis laboratory (MAL) is difficult. Wearable pressure insoles, by providing normal ground reaction force (NGrF), can be used to quantify loading gait asymmetry in real life conditions. This asymmetry, considered as an indicator of the quality of the gait, is useful for physicians to monitor the rehabilitation progress or the prosthetic fitting suitability. The study aimed at quantifying the reliability of NGrF measurement and assessing the gait asymmetry of transfemoral amputee people with Pedoped® insoles against force plates. Walking speed effect was also evaluated on gait asymmetry for transfemoral amputee people (TFP). Material and methods In a MAL, five active TFP walked at three self-selected speeds on level ground wearing Pedoped® insoles. Reliability was assessed by comparing NGrF obtained from both systems with Bland-Altman plots, normalized RMSE (NRMSE) and correlation coefficient. Gait loading asymmetry was computed by Absolute Symmetry Index in loading at the three self-selected speeds with insoles. Results The mean NRMSE of NGrF was 7.2% (± 2.8%) and 9.8% (± 3.5%); and coefficient correlation was 0.91 and 0.95 for the prosthetic side and the intact side respectively. Loading asymmetry increased significantly with walking speed for each specific variable of NGrF. Discussion–conclusion After overcoming the calibration problem in amputee population, Pedoped® insoles could be easily used for gait asymmetry follow-up during rehabilitation.